Leonardo was a professional classical guitarist until a motorcycle accident left him disabled. After long months of therapy, he hired an experienced luthier and started a small shop to make and sell Spanish guitars. The guitars sell for $700, and the fixed monthly operating costs are as follows: Rent and utilities Wages and benefits to luthier Other expenses Leonardo's accountant told him about contribution margin ratios, and Leonardo understood clearly that for every dollar of sales, $0.60 went to cover his fixed costs, and anything above that point was profit. $800 2100 472 What is the amount of revenue Leonardo should earn each month to break even? (Round your answer to the nearest dollar.) Select one: A. $8430 B. $4833 C. $5620 D. $4287